Lexmark C910 User Reference Manual page 201

Install <device>
or Cancel Job
What this message means:
The printer is requesting that a specified device be installed so it can print a job.
What you can do:
•
Turn the printer off, install the specified device, and restart the printer.
•
Press to open the Job Menu and cancel the current job.
Menu
Invalid Engine Code
What this message means:
The printer engine code has not been programmed or is not valid.
What you can do:
Call for service.
See also:
Calling for service
Invalid
Network <x> Code
What this message means:
The code in an internal print server is not valid. The printer cannot receive and process jobs
until valid code is programmed into the internal print server.
What you can do:
Download valid code to the printer internal print server.
Note: You can download network code while this message is displayed.
Invalid Standard
Network Code
199